Some semiconductor chips use bump electrodes. By direct connection of the bump electrodes and electrodes of a circuit board, semiconductor chips can be mounted on the circuit board. Such semiconductor chips are in general collectively formed on a semiconductor wafer, and undergo an electrical inspection before the semiconductor wafer is separated into respective chips.
In this sort of the electrical inspection, a plurality of chip regions which are devices under test are connected to a tester through a probe assembly in which a plurality of probes are provided to be in contact with electrodes in each chip region on the semiconductor wafer.
Each probe of the probe assembly has an arm portion where a tip is provided. One end of this arm portion is secured to a circuit of a probe base of the probe assembly, and the arm portion extends laterally from the surface of the probe assembly at a distance substantially along the surface of the probe base. At the other end of the arm portion, the tip is formed in a direction to be away from the surface of the probe base (see Patent Document 1).
The probe assembly is relatively pressed toward the semiconductor wafer so that the tip of each probe may contact the corresponding bump electrode. At this time, an overdrive force is applied to each probe so that a slight flexural deformation may occur to the arm portion for a secure contact of each probe with corresponding bump electrode.
In the invention according to Patent Document 1, a projected portion for preventing an excessive deformation of the probe is provided between the probes and the probe base. By a deformation regulating action of this projected portion, an excessive deformation of the arm portion due to excessive overdrive force is controlled, thereby preventing damage to the probe due to the excessive deformation of the arm portion.
However, there is a fear that, if a foreign matter such as a waste of a bump material remains in the vicinity of the bump electrode in the chip region, the foreign matter might hit the arm portion of the probe, even if the vicinity of the tip portion of the arm portion of each probe is deformed toward the chip region of the semiconductor wafer so as to apply a proper overdrive force to the arm portion.
Where the semiconductor chip is an IC driver of a liquid crystal panel, the size and arrangement pitch of the electrodes with which the probes are brought into contact are of a very small value like several decades μm. Therefore, for each probe of the probe assembly for use in such an electrical inspection, a needle member with a small diameter corresponding to the thickness dimension is used. Thus, when subjected to a strong pressing force from the foreign matter when brought into contact with the foreign matter remaining around the electrode, the probes are prone to damage. For this reason, there has been a demand for a probe assembly capable of surely preventing damage to a probe due to interference between such a foreign matter remaining around an electrode and the probe.
Patent Document 1    Japanese Patent Appln. Public Disclosure No. 2002-340932